ADXL362 Expected Sensitivity Range

In production we do a calibration of the ADXL362 by taking static +/- 1G and 0G readings for each axis. We then do a calibration check to make sure they are within the expected range for the ADXL362. The data sheet specifies the nominal sensitivity to be 250 LSB/g for +/-8g range, with a sensitivity calibration range of +/-10%. We have our limits for each axis set to 220-280 LSB/g, which is +/-12% of the nominal 250LSB/g. We are getting some units that have sensitives as low as 215 LSB/g. I want to verify that this is expected, and why we might see this behavior.

To get the sensitivity for each axis we take the +1G reading minus the -1G reading and divide by 2.

Just a quick idea, you might want to look at +1g and -1g (instead of 0g) orientations and see if that makes a difference in your observation of the scale factor. When you use 0g, you are very dependent on how precise the orientation is, as well as how precisely you are imposing a 90 degree orientation change from 0g to 1g orientations. When you use +1g and -1g, you will have less dependency on the orientation accuracy and the bias is easier to separate (from absolute orientation error at 0g).

Thanks Mark for your suggestion. I checked our characterization database and the sensitivity should fall in the range of 225 - 275 LSB/g for +/-8g as per the spec on the datasheet. Please let us know if Marks suggestion works for you, otherwise you may want to contact the local ADI quality representative for further investigation.